1. Field of the Field
The present invention relates to electrical connectors providing a plurality of contacts and, more particularly, to an electrical connector which allows for 360.degree. rotation, while providing interruption-free electrical continuity.
2. Description of the Prior Art
It can be quite cumbersome to handle an electrical device or appliance that relies on a source at, or that transmits a signal to, a remote location. For example, a musician may be inclined to move about with an electrical musical instrument, such as an electrical guitar, twisting and tangling the signal transmission cord. This twisting and tangling creates radial energy in the cord. Handling of other devices, such as microphones and headphone, or appliances, such as power tools and household appliances, may be troublesome as well when the user of the device or appliance is moving about. Wireless devices have been devised to omit the need for transmission cords and eliminate the problems associated with the same. Wireless devices and appliances are known to be costly. Moreover, wireless devices and appliances require an independent power source which requires periodic replacement or recharging. Further, wireless devices and appliances may require a transmitting or receiving means which, in combination with the source, may be burdensome. An alternative to a wireless device or appliance having a power or transmission cord which resists twisting and tangling could prove to be invaluable.
There have been several attempts to devise a device having electrical contacts which provide freedom of movement. For example, U.S. Pat. No. 4,850,880, issued Jul. 25, 1989 to Charles D. Zayat, Jr. et al., discloses a device having two separate sets of contacts and a pivotal axis allowing 360.degree. of rotational freedom between the two sets of contacts. The device is configured to release radial mechanical energy stored in a cord due to repeated twisting of the device attached to the cord. The device provides a continuous electrical connection between the two sets of contacts, by providing rotary contacts which allow interruption free electrical continuity during the full 360.degree. of rotation. The device utilizes a center core member carrying one set of contacts rotatably mounted within an outer housing carrying complementary contacts. The core and housing members provide free rotation to avoid tangling.
Another rotatable coupling is shown in U.S. Pat. No. 4,557,536, issued Dec. 10, 1985 to Jan V. M. Geurts. Geurts discloses a rotatable electrical coupling having a cylindrical housing enclosing two resilient contact members and a circumferential groove formed in its inner surface. The cable holder has two slip rings respectively cooperating with the two contact members. The slip rings are formed as coaxial cylindrical conductors of different diameters. A connection cable is embedded in the cable holder and has two conducting cores respectively electrically connected to the two slip rings. A hollow substantially cylindrical insulating body electrically separates the two slip rings from each other.
Yet another apparatus for preventing the twisting of electrical cables is shown in U.S. Pat. No. 4,894,014, issued Jan. 16, 1990 to Joseph Palus et al. Palus et al. discloses an apparatus constructed with bearing assemblies for conducting electrical current from a fixed cable end to a rotatable cable end. The apparatus includes a housing having fixed and rotatable cable clamping devices attached thereto. The housing and the cable clamping devices cooperate to transmit tensile loads on the cable through the housing, thereby preventing wear and damage to moving electrical contacts. An idler bearing is employed to minimize torsional strains on the cable conductors by permitting the cable to rapidly change position within the housing.
Unlike the apparatuses disclosed in the aforementioned patents, U.S. Pat. No . 5,074,796, issued Dec. 24, 1991 to Andrew L. Carter, discloses a stacking multiple contact plug and socket electrical connector. The connector has a central body with a plug extending outward from one face thereof, and a socket recessed inward within an opposite face thereof. The plug includes multiple electrically conductive circular contacts rings thereabout. The socket includes multiple electrical wiper contacts spaced along an electrically insulating inner wall therein for contacting the circular contact rings of the plug. The plug and socket connector allows for rotation of the plug within the socket without loss of electrical contact with the socket.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.